1999 Mazda 626 Smells Like Gas

Identifying Potential Causes of Gas Smells in Your 1999 Mazda 626 and Essential Safety Measures

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
15% chance it's the
Gas Cap
0%
40% chance it's the
Emissions Control System
0%
45% chance it's
Something else
The most common reasons a 1999 Mazda 626 smells like gas are the gas cap, the fuel system, or the emissions control system.
  • Gas Cap: A loose or damaged gas cap can cause fuel vapors to escape, triggering the check engine light and potentially affecting fuel system pressure.
  • Emissions Control System: A faulty emissions control system can lead to increased hydrocarbon emissions and trigger the check engine light due to malfunctioning components like the EGR valve or O2 sensors.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 1999 Mazda 626 smells like gas?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

A failing catalytic converter can cause a vehicle to fail emissions tests and turn on the check engine light. The exhaust might have an unusual smell. A restricted catalytic converter can result in a loss of engine power.

» LEARN MORE: How to tell if your catalytic converter is failing

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. The canister may also cause difficulty starting the engine, a rough idle, and poor fuel mileage.

When the fuel filter begins to clog, the engine suffers from fuel starvation. This will cause a significant reduction in power and may also cause a misfire. These conditions may be intermittent, or constant and worsen over time. As the issue progresses, the engine may being to stall immediately after starting, fail to start, hesitate under throttle, or stall at particular angles on hills.

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. A fuel tank leak may also cause difficulty starting the engine, a rough idle, and poor fuel mileage. When a fuel tank is simply corroded to the point of failure, the exterior tank condition rarely shows damage. The inside of the fuel tank will be rusted or corroded, and rust flakes or other debris may be floating in the fuel.

For most vehicles, the only symptom will be a check engine light or fuel tank filler cap light illuminating on the driver instrument cluster. This is to signal that there is an evaporative emissions (EVAP) leak. In some situations, the vehicle may take longer than normal to start, or, more rarely, the engine may not start at all. on-board diagnostic (OBD) trouble codes will refer to EVAP system failures such as a small or massive EVAP system leak. Lastly, the powertrain control module may notice a lean running condition, which could even lead to random and infrequent misfires.

What are the potential causes of a gas smell in a 1999 Mazda 626, and how should I diagnose the issue?

When diagnosing a gas smell in your 1999 Mazda 626, it's essential to adopt a systematic approach that prioritizes simpler checks before delving into more complex issues. Start by inspecting the fuel system for any visible leaks, focusing on the fuel lines, injectors, and tank, as these are common culprits. If no leaks are found, assess the fuel injectors for signs of malfunction, such as poor fuel economy or rough idling, which could indicate they need replacement. Next, examine the evaporative emissions system, particularly the charcoal canister and purge valve, as failures here can also lead to gas odors. Don’t overlook the exhaust system; any leaks can allow fumes to enter the cabin, so check for cracks or loose connections. Finally, ensure that the ventilation system is clear of blockages and that the cabin air filter is clean, as these can trap odors inside the vehicle. By following this diagnostic approach, you can effectively identify the source of the gas smell and determine whether it’s a DIY fix or if professional assistance is needed.

What could be causing the gas smell in my 1999 Mazda 626?

If you're experiencing a gas smell in your 1999 Mazda 626, it's essential to understand the potential causes to address the issue effectively. A fuel leak is often the primary suspect, which can originate from the fuel tank, fuel lines, or fuel injectors. Additionally, a malfunctioning fuel injector may leak fuel into the engine compartment, contributing to the odor. It's also important to check the gas cap; if it's loose, damaged, or missing, it can allow fuel vapors to escape. Another area to investigate is the evaporative emissions control system, where components like the charcoal canister or purge valve may fail, leading to gas smells inside the vehicle. Lastly, don't rule out the exhaust system, as leaks or issues with the catalytic converter can sometimes produce a gas-like odor. While some of these issues may be manageable through DIY repairs, it's advisable to consult a professional mechanic for a thorough inspection to ensure your safety and the proper functioning of your vehicle.

How urgent is it to address the gas smell in my 1999 Mazda 626?

When you detect a gas smell in your 1999 Mazda 626, it is crucial to act swiftly due to the serious safety risks involved. Gas leaks not only pose a significant fire hazard but can also lead to harmful health effects from inhaling toxic fumes. Prolonged exposure can result in symptoms such as dizziness and nausea, which are not to be taken lightly. Additionally, neglecting this issue can exacerbate the problem, potentially leading to more extensive and costly repairs down the line. For DIY enthusiasts, it’s essential to inspect the fuel lines, connections, and the fuel tank for any signs of leaks or damage. If you are not comfortable performing these checks, it is advisable to seek professional assistance immediately. Prioritizing this issue will not only safeguard your health and safety but also help maintain the integrity of your vehicle.

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